Tripod supporting a framing table for concrete works

ABSTRACT

A jack comprises an inverted tripod divided substantially in half in two portions of substantially equal height, the lower portion including a jack structure of small compass.

United States Patent Bournazel Aug. 13, 1974 TRIPOD SUPPORTING A FRAMING TABLE [56] References Cited FOR CONCRETE WORKS UNITED STATES PATENTS [75] Inventor: Jacques Bournazel, Wissous, France 1,259,120 3/1918 Martin 254/86 R 3,096,065 7 1963 H 248 354 S [73] Assignee: Societe Pour Llndustrialisation du 3,448998 611916 832 I I v D D 251/86 R Mater Essone, France 3,655,161 4/1972 Schueler.... 248/354 5 3,667,730 6/1972 Kollmar.... 254/86 R [22] Sept 1972 3,713,259 1/1973 Tkach 248/354 5 [21] Appl. No.: 286,961

Primary Examiner-William Scholtz [30] Foreign Application Priority Data Attorney, Agent, or Fzrm-lmme & Smiley June 1, 1972 France 72.19719 57 ABSTRACT [52] U S Cl 248/354 S A jack comprises an inverted tripod divided substan- [511 RC1. "F16!" 13/00 tially in half in two portions of Substantially equal [58] Field 254/86 H height, the lower portion including a jack structure of small compass.

4 Claims, 5 Drawing Figures PATENTEU AUG] 31974 3. 829 O 53 SHEET 1 BF 3 FKM PAIENIEBAUGI sum SHEET 2 OF 3 TRIPOD SUPPORTING A FRAMING TABLE FOR CONCRETE WORKS BACKGROUND OF THE INVENTION This invention relates to a jack for supporting a framing table for concrete works or the like.

In modern construction, civil engineering companies utilize framing tables to pour the concrete at the different levels of the dwelling houses or similar buildings. Said tables are constituted by struts or scaffoldings, the same supporting a floor on which the concrete is poured.

The disadvantage of the known embodiments consists of the complexity of the strutting which requires a lot of material and of which the placing and removal require skilled work-men. Besides, it is practically impossible to pass under the framing.

SUMMARY OF THE INVENTION This invention copes with the above mentioned disadvantages, by providing an inverted tripod jack for supporting the framing, and of which the placing and removal quickly can be made, while having a small bearing portion on the ground.

The above result is obtained according to the invention, due to the fact that the tripod the three sections thereof being grouped at the base, the same being provided with a jack and a roller can be folded to halfheight, thus making easier the removal of the framing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a side elevational view of a tripod jack according to the invention;

FIG. 2 is a top view of the tripod jack of FIG. 1;

FIG. 3 is a plan view of the joint, taken along line III- III of FIG. 1;

FIG. 4 is an enlarged cross-section view taken along line IVIV of FIG. 1, and

FIG. 5 is an enlarged cross-section view of a variant of FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION The tripod jack supporting a framing, according to the invention, and shown in FIGS. 1 and 2, is composed of three rigid tubes, 1, 2, 3; the tubes 2 and 3 being disposed in substantially vertical planes, perpendicularly intersecting within tube 1 so that tube 3 is behind tube 1 and not shown in FIG. 1. Tube 1 is vertical and tubes 2 and 3 are oblique or angularly disposed relative to tube 1 and they are joined through welding at the lower ends thereof to a polygonal plate 4. The center of plate 4 comprises an internally threaded bore aligned with the tube 1. The threaded bore adjustably receives a threaded rod 5 with fast pitch and threadably supporting a wing nut 6 having a plurality of wings 7. The lower end of the threaded rod 5 is secured to a plate 8 for bearing on the ground. A sleeve 9, vertical and positioned parallel to the tube 1 by means of struts 10, ll, 12, slidably receives a tube 13 which is provided at its lower end with a roller 14. Holes in sleeve 9 and tube 13 receive a pin 15 to secure the roller at the desired height.

' The upper ends of the three tubes 1, 2, 3, connected by two horizontal struts 16, I7, are each provided with a plate made of iron 18, 19, (FIG. 2) supporting fixing means ensuring connection between the tripod and the beams of a framing table. Said fixing means are shown in detail in FIGS. 4 and 5.

FIG. 4 shows means for securing the tripod jack to v the transverse beam of a framing table. Said means essentially are constituted by a U-shaped bracket 21 which straddles the transverse beam 24 of a framing and of which the two branches 21a and 21b are traversed by a threaded rod 22 with fast pitch, supporting at each of the two ends thereof a nut 23. This U-shaped bracket 21 is supported on another U-shaped bracket 25 which relatively is turned by carries a bolt 26 for connection with the plates 18 and 20. In order to maintain the longitudinal beams on the tripod jack, as shown in FIG. 5, a threaded rod 27 having a head 28 and a fixed square-shaped spacer 29 spaced from said head, is inserted between two longitudinal beams, said spacer 29 preventing rotation of said rod during the tightening of a nut 30 after having been placed between two longitudinal beams. The tightening of the two fixing devices as above described is made by means of eyelet-nuts 30 which does not require any elaborate tools.

To facilitate positioning and removal of the jack, in accordance with the invention it is divided at substantially half-height of the tripod and the two portions provided with a hinged joint enabling-folding of the lower portion of said tripod on the upper portion and to maintain it into said position by means of small chains 31, 32 with hooks 33, 34. Said joint is shown in detail in FIG. 3 the three main tubes 1, 2, 3 of the tripod into two substantially equal half portions and having fixed on the ends of each half portion an L-shaped plate 35, 36 connecting the ends of tubes 1, 2 and I, 3. The plates 35, 36 are connected together by one of two hinges 37, 38. According to the position of the spindle 39 of the hinge 38, the lower portion of the tripod can rotate in either way. The locking of the joint is made by means of two bolts 40 and 41.

The invention thus creates a tripod jack supporting a framing for concrete works, the placing of which being very quickly made due to its simple fixing to the transverse and longitudinal beams of the framing and due to the easy adjustment of the height by means of the threaded rod or jack. When the framing has to be moved at the same level during works, just the jacks have to be loosened whereby the rollers bear on the ground said rollers having been previously set at the desired height and the framing table can be rolled along to the place designated for its reutilization. During the operation consisting of removing the whole framing, it frequently happens that said operation meets with some difficulties due to the presence of window basements or small walls. With the tripods made according to the invention, said difficulties are easily overcome due to the fact that the lower portion of the tripod can be folded back in the desired direction on the upper portion and be maintained into that position by the small chains. According to the desired bearing surface, four, six or more tripods are utilized. Due to the fact that the bearing surface on the ground of said tripods is relatively small, it is not difficult to manouver under the framing.

The invention is not restricted to the embodiment, shown and described in detail, for various modifications can moreover be applied to it within the scope of the invention as defined in the appended claims.

I claim:

1. A jack comprising an inverted tripod frame including a substantially vertical support member and two angularly disposed upwardly extending support members having their lower ends rigidly fixed with the lower end portion of said vertical member, the upper ends of said members being rigidly secured to a load bearing member, jack means cooperative with the lower end of said frame for varying selectively the vertical location of said load bearing member, said frame being severed in termediate its length into two portions each having a bearing element secured to the ends of said support members, and hinge means connecting said bearing el ements to enable engagement between said bearing elements to position the portions of said support members in alignment and permit swinging of one frame portion jacks to constitute a composite assembly of jacks. 

1. A jack comprising an inverted tripod frame including a substantially vertical support member and two angularly disposed upwardly extending support members having their lower ends rigidly fixed with the lower end portion of said vertical member, the upper ends of said members being rigidly secured to a load bearing member, jack means cooperative with the lower end of said frame for varying selectively the vertical location of said load bearing member, said frame being severed intermediate its length into two portions each having a bearing element secured to the ends of said support members, and hinge means connecting said bearing elements to enable engagement between said bearing elements to position the portions of said support meMbers in alignment and permit swinging of one frame portion out of alignment for movement of said jack.
 2. A jack according to claim 1 comprising roller means secured to the lower end of said frame to support and facilitate movement thereof when said jack means is retracted.
 3. A jack according to claim 1 wherein said angularly disposed support members respectively are located in vertical planes which perpendicularly intersect in said vertical support member.
 4. A jack according to claim 3 wherein said load bearing member is L-shaped and has means at the free ends thereof for attachment to like members of like jacks to constitute a composite assembly of jacks. 